Some conventional systems for detecting motion use a time domain switched inertial sensor that employs tunneling proximity switches. The purpose is to detect motion without inhibiting the motion. The system notes when a mass on a spring harmonic oscillator under the influence of external inertial forces passes known displacement locations. The technology requires a digital trigger when the oscillating proof mass passes the known locations. Some of these proximity switches create pA to nA signals, which require amplification before they can be used as digital triggers.